locations was important to minimize the
dose to residents. Thus, a
162° 20° &
(Gene) Triterspucchi .
(Floral Elugelab , \
(Edna) Bok imwotme
(Daisy) Louj -
Bokaidetkdrk (Helen)
Boken (Irene)
Enjehi (Janet)
resurvey of Bikini and Eneu Islands was conducted
in 1975 including
collection of available samples to evaluate expos
ure via food chains as
well as by external gamma. Although very
few food crops were available
Mijikadrek (Katel
Kidrinen (Lucy?
(Mag )
=
Ocean
roe “
AH,
" Me,
>
Luyjor (Peart)
{Salty}
7 .Aaomon
_.
:
ewetein
}
(Ol
Aaranbiru
%
(Vera)
%
= 270
Lojwa (Ursula)
Billse (Wilma)
Ocean
~
“
11°30 N
-
a
0a
i
(Leroy) Biken .\
eee
os
- Runit (¥vonne}
Photo tower (Oscar) Y
*
a
Cn
Volare
ae
--
~
30N
(Bruce)
t Sinieni
J (Clyde)
Passage
Jedrol .9
Lagoon
‘TA
5
2
2 3
4
6
Boken lirvind
Mut
fHenryvh ikuren
Japtan
(David)
Deep
Entrance
Ut
so
Enewetak (Ered)
.
{Glenn}
o
G/
Medren (Elmer)
{Keith) Kidrinen (James) Prbewon
1
{Alvin
> Ananij
ra
Lene
Enewetak Aroll
Neutical miles
Jinedral —_4
aie
9& “ °
Wide
Passage
.
doses
estimated for Eneu Island [2-5]. As a result
, a field program was
initiated in 1977 at Bikini Atoll. Subsistence
crops were planted on
Eneu Island to supplement the coconut trees,
which had been planted
on both islands in 1970
and were due to begin bearing fruit withi
n the
year, to measure the radionuclide concentrat
ion in subsistence foods.
In 1977,
a clean-up program was also begun
at Enewetak
o.,
_
Southwest
110
Federal guidelines and were about 8 to
10 times greater than
SoReal
90 = Coral Head (Mack)
2
to directly measure the radionuclide concentrat
ions on either island,
the results did indicate that estimated doses for
Bikini Island exceeded
Bokenelab (Mary)
Ele {Nancy}
jw
wl.
=}8
Fig. 3, Map of Enewetak Atoll,
Thus, the survey was conducted in 1972 and 1973 and the radiological
analysis completed [1]. The analysis indicated that the terrestrial food
chain waspotentially the most significant exposure pathway, However,
Atoll
directed toward removing scrap and debris remai
ning from World War
Il and the subsequent test series. Also a radiol
ogical clean-up, which
consisted of soil removal, was conducted on
those islands that had the
highest transuranic radionuclide concentratio
ns. The clean-up was
completed in 1979. External £amma measu
rements were made and
soil samples were analyzed for the critical radion
uclides.
Concurrently with the ongoing programs
at Bikini and Enewetak
Atolls, the U.S. Government decided to
evaluate the radiological
conditions of two islands and ten atolls
downwind of the Enewetak
and Bikini proving ground prior to the
termination of the United
Nations Trust Territory agreement under
which the United States
administer
s Micronesia. Thus in 1978, we condu
cted the
Northern
Marshall Islands Radiological Survey (NMIR
S)of Rongelap, Utirik,
Rongerik, Wotho, Likiep, Ailuk, Mejit,
Ailinginae, Ujelang, Bikar,
Taka, and Bikini (see Fig. 1). The
survey included aerial external
famm
a measurements and the collection ofsoil,
terrestrial, and marine
samples for radionuclide analysis to deter
mine the radiological dose
from all exposure pathways [6-9].
The methods and models used to estimate
the doses to a returning
population
the analysis also identified areas where additional data were needed
to make more precise dose estimates.Therefore, a field program was
begun at Enewetak Atoll in 1975 to develop the required data base.
Crops historically used by the Marshallese for subsistence were planted
on Enjebi Island to determine the concentration of radionuclides in
locally. grown foods and the concentration ratio between the radionu-
have acted on
the source-team radionuclides for nearly
30 y, the data bases developed
for the models, and the results of the radiol
ogical dose analyses at the
various atolls are described here.
were initiated to evaluate the cycling of radionuclides and to determine
Major Radionuclides
clide concentration in edible foods and soil. In addition, experiments
the residence time in the atoll ecosystem.
There were also plans in 1975 to starts secondof
ikint Island at Bikini Atoll. However, external gamma measurements
available from earlier surveys indicated that selection of housing
42
in an environment where natural proces
ses
The most significant radionuclides at
the atolls in order of the
:
Contribs:
'
; or,
7
u,
“"Am, and ™Co. The Cs, both from exter
nal gamma exposure and
uptake into food crops, accounts for over
90% of the total estimated
43